Are ladybugs herbivorous

Yes, some ladybugs are herbivorous even though the vast majority are insectivorous.

Specifically, ladybugs tend to eat garden insect pests, such as aphids and mealybugs. But there are also some such as the pink-spotted ladybug (Coleomegilla maculate) that feeds on pollen and therefore is not an insectivore. Probably the most infamous of the vegetarian ladybugs is the Mexican bean beetle (Epilachna varivestis).